sock.c revision 43815482370c510c569fd18edb57afcb0fa8cab6
1/*
2 * INET		An implementation of the TCP/IP protocol suite for the LINUX
3 *		operating system.  INET is implemented using the  BSD Socket
4 *		interface as the means of communication with the user level.
5 *
6 *		Generic socket support routines. Memory allocators, socket lock/release
7 *		handler for protocols to use and generic option handler.
8 *
9 *
10 * Authors:	Ross Biro
11 *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12 *		Florian La Roche, <flla@stud.uni-sb.de>
13 *		Alan Cox, <A.Cox@swansea.ac.uk>
14 *
15 * Fixes:
16 *		Alan Cox	: 	Numerous verify_area() problems
17 *		Alan Cox	:	Connecting on a connecting socket
18 *					now returns an error for tcp.
19 *		Alan Cox	:	sock->protocol is set correctly.
20 *					and is not sometimes left as 0.
21 *		Alan Cox	:	connect handles icmp errors on a
22 *					connect properly. Unfortunately there
23 *					is a restart syscall nasty there. I
24 *					can't match BSD without hacking the C
25 *					library. Ideas urgently sought!
26 *		Alan Cox	:	Disallow bind() to addresses that are
27 *					not ours - especially broadcast ones!!
28 *		Alan Cox	:	Socket 1024 _IS_ ok for users. (fencepost)
29 *		Alan Cox	:	sock_wfree/sock_rfree don't destroy sockets,
30 *					instead they leave that for the DESTROY timer.
31 *		Alan Cox	:	Clean up error flag in accept
32 *		Alan Cox	:	TCP ack handling is buggy, the DESTROY timer
33 *					was buggy. Put a remove_sock() in the handler
34 *					for memory when we hit 0. Also altered the timer
35 *					code. The ACK stuff can wait and needs major
36 *					TCP layer surgery.
37 *		Alan Cox	:	Fixed TCP ack bug, removed remove sock
38 *					and fixed timer/inet_bh race.
39 *		Alan Cox	:	Added zapped flag for TCP
40 *		Alan Cox	:	Move kfree_skb into skbuff.c and tidied up surplus code
41 *		Alan Cox	:	for new sk_buff allocations wmalloc/rmalloc now call alloc_skb
42 *		Alan Cox	:	kfree_s calls now are kfree_skbmem so we can track skb resources
43 *		Alan Cox	:	Supports socket option broadcast now as does udp. Packet and raw need fixing.
44 *		Alan Cox	:	Added RCVBUF,SNDBUF size setting. It suddenly occurred to me how easy it was so...
45 *		Rick Sladkey	:	Relaxed UDP rules for matching packets.
46 *		C.E.Hawkins	:	IFF_PROMISC/SIOCGHWADDR support
47 *	Pauline Middelink	:	identd support
48 *		Alan Cox	:	Fixed connect() taking signals I think.
49 *		Alan Cox	:	SO_LINGER supported
50 *		Alan Cox	:	Error reporting fixes
51 *		Anonymous	:	inet_create tidied up (sk->reuse setting)
52 *		Alan Cox	:	inet sockets don't set sk->type!
53 *		Alan Cox	:	Split socket option code
54 *		Alan Cox	:	Callbacks
55 *		Alan Cox	:	Nagle flag for Charles & Johannes stuff
56 *		Alex		:	Removed restriction on inet fioctl
57 *		Alan Cox	:	Splitting INET from NET core
58 *		Alan Cox	:	Fixed bogus SO_TYPE handling in getsockopt()
59 *		Adam Caldwell	:	Missing return in SO_DONTROUTE/SO_DEBUG code
60 *		Alan Cox	:	Split IP from generic code
61 *		Alan Cox	:	New kfree_skbmem()
62 *		Alan Cox	:	Make SO_DEBUG superuser only.
63 *		Alan Cox	:	Allow anyone to clear SO_DEBUG
64 *					(compatibility fix)
65 *		Alan Cox	:	Added optimistic memory grabbing for AF_UNIX throughput.
66 *		Alan Cox	:	Allocator for a socket is settable.
67 *		Alan Cox	:	SO_ERROR includes soft errors.
68 *		Alan Cox	:	Allow NULL arguments on some SO_ opts
69 *		Alan Cox	: 	Generic socket allocation to make hooks
70 *					easier (suggested by Craig Metz).
71 *		Michael Pall	:	SO_ERROR returns positive errno again
72 *              Steve Whitehouse:       Added default destructor to free
73 *                                      protocol private data.
74 *              Steve Whitehouse:       Added various other default routines
75 *                                      common to several socket families.
76 *              Chris Evans     :       Call suser() check last on F_SETOWN
77 *		Jay Schulist	:	Added SO_ATTACH_FILTER and SO_DETACH_FILTER.
78 *		Andi Kleen	:	Add sock_kmalloc()/sock_kfree_s()
79 *		Andi Kleen	:	Fix write_space callback
80 *		Chris Evans	:	Security fixes - signedness again
81 *		Arnaldo C. Melo :       cleanups, use skb_queue_purge
82 *
83 * To Fix:
84 *
85 *
86 *		This program is free software; you can redistribute it and/or
87 *		modify it under the terms of the GNU General Public License
88 *		as published by the Free Software Foundation; either version
89 *		2 of the License, or (at your option) any later version.
90 */
91
92#include <linux/capability.h>
93#include <linux/errno.h>
94#include <linux/types.h>
95#include <linux/socket.h>
96#include <linux/in.h>
97#include <linux/kernel.h>
98#include <linux/module.h>
99#include <linux/proc_fs.h>
100#include <linux/seq_file.h>
101#include <linux/sched.h>
102#include <linux/timer.h>
103#include <linux/string.h>
104#include <linux/sockios.h>
105#include <linux/net.h>
106#include <linux/mm.h>
107#include <linux/slab.h>
108#include <linux/interrupt.h>
109#include <linux/poll.h>
110#include <linux/tcp.h>
111#include <linux/init.h>
112#include <linux/highmem.h>
113
114#include <asm/uaccess.h>
115#include <asm/system.h>
116
117#include <linux/netdevice.h>
118#include <net/protocol.h>
119#include <linux/skbuff.h>
120#include <net/net_namespace.h>
121#include <net/request_sock.h>
122#include <net/sock.h>
123#include <linux/net_tstamp.h>
124#include <net/xfrm.h>
125#include <linux/ipsec.h>
126
127#include <linux/filter.h>
128
129#ifdef CONFIG_INET
130#include <net/tcp.h>
131#endif
132
133/*
134 * Each address family might have different locking rules, so we have
135 * one slock key per address family:
136 */
137static struct lock_class_key af_family_keys[AF_MAX];
138static struct lock_class_key af_family_slock_keys[AF_MAX];
139
140/*
141 * Make lock validator output more readable. (we pre-construct these
142 * strings build-time, so that runtime initialization of socket
143 * locks is fast):
144 */
145static const char *const af_family_key_strings[AF_MAX+1] = {
146  "sk_lock-AF_UNSPEC", "sk_lock-AF_UNIX"     , "sk_lock-AF_INET"     ,
147  "sk_lock-AF_AX25"  , "sk_lock-AF_IPX"      , "sk_lock-AF_APPLETALK",
148  "sk_lock-AF_NETROM", "sk_lock-AF_BRIDGE"   , "sk_lock-AF_ATMPVC"   ,
149  "sk_lock-AF_X25"   , "sk_lock-AF_INET6"    , "sk_lock-AF_ROSE"     ,
150  "sk_lock-AF_DECnet", "sk_lock-AF_NETBEUI"  , "sk_lock-AF_SECURITY" ,
151  "sk_lock-AF_KEY"   , "sk_lock-AF_NETLINK"  , "sk_lock-AF_PACKET"   ,
152  "sk_lock-AF_ASH"   , "sk_lock-AF_ECONET"   , "sk_lock-AF_ATMSVC"   ,
153  "sk_lock-AF_RDS"   , "sk_lock-AF_SNA"      , "sk_lock-AF_IRDA"     ,
154  "sk_lock-AF_PPPOX" , "sk_lock-AF_WANPIPE"  , "sk_lock-AF_LLC"      ,
155  "sk_lock-27"       , "sk_lock-28"          , "sk_lock-AF_CAN"      ,
156  "sk_lock-AF_TIPC"  , "sk_lock-AF_BLUETOOTH", "sk_lock-IUCV"        ,
157  "sk_lock-AF_RXRPC" , "sk_lock-AF_ISDN"     , "sk_lock-AF_PHONET"   ,
158  "sk_lock-AF_IEEE802154",
159  "sk_lock-AF_MAX"
160};
161static const char *const af_family_slock_key_strings[AF_MAX+1] = {
162  "slock-AF_UNSPEC", "slock-AF_UNIX"     , "slock-AF_INET"     ,
163  "slock-AF_AX25"  , "slock-AF_IPX"      , "slock-AF_APPLETALK",
164  "slock-AF_NETROM", "slock-AF_BRIDGE"   , "slock-AF_ATMPVC"   ,
165  "slock-AF_X25"   , "slock-AF_INET6"    , "slock-AF_ROSE"     ,
166  "slock-AF_DECnet", "slock-AF_NETBEUI"  , "slock-AF_SECURITY" ,
167  "slock-AF_KEY"   , "slock-AF_NETLINK"  , "slock-AF_PACKET"   ,
168  "slock-AF_ASH"   , "slock-AF_ECONET"   , "slock-AF_ATMSVC"   ,
169  "slock-AF_RDS"   , "slock-AF_SNA"      , "slock-AF_IRDA"     ,
170  "slock-AF_PPPOX" , "slock-AF_WANPIPE"  , "slock-AF_LLC"      ,
171  "slock-27"       , "slock-28"          , "slock-AF_CAN"      ,
172  "slock-AF_TIPC"  , "slock-AF_BLUETOOTH", "slock-AF_IUCV"     ,
173  "slock-AF_RXRPC" , "slock-AF_ISDN"     , "slock-AF_PHONET"   ,
174  "slock-AF_IEEE802154",
175  "slock-AF_MAX"
176};
177static const char *const af_family_clock_key_strings[AF_MAX+1] = {
178  "clock-AF_UNSPEC", "clock-AF_UNIX"     , "clock-AF_INET"     ,
179  "clock-AF_AX25"  , "clock-AF_IPX"      , "clock-AF_APPLETALK",
180  "clock-AF_NETROM", "clock-AF_BRIDGE"   , "clock-AF_ATMPVC"   ,
181  "clock-AF_X25"   , "clock-AF_INET6"    , "clock-AF_ROSE"     ,
182  "clock-AF_DECnet", "clock-AF_NETBEUI"  , "clock-AF_SECURITY" ,
183  "clock-AF_KEY"   , "clock-AF_NETLINK"  , "clock-AF_PACKET"   ,
184  "clock-AF_ASH"   , "clock-AF_ECONET"   , "clock-AF_ATMSVC"   ,
185  "clock-AF_RDS"   , "clock-AF_SNA"      , "clock-AF_IRDA"     ,
186  "clock-AF_PPPOX" , "clock-AF_WANPIPE"  , "clock-AF_LLC"      ,
187  "clock-27"       , "clock-28"          , "clock-AF_CAN"      ,
188  "clock-AF_TIPC"  , "clock-AF_BLUETOOTH", "clock-AF_IUCV"     ,
189  "clock-AF_RXRPC" , "clock-AF_ISDN"     , "clock-AF_PHONET"   ,
190  "clock-AF_IEEE802154",
191  "clock-AF_MAX"
192};
193
194/*
195 * sk_callback_lock locking rules are per-address-family,
196 * so split the lock classes by using a per-AF key:
197 */
198static struct lock_class_key af_callback_keys[AF_MAX];
199
200/* Take into consideration the size of the struct sk_buff overhead in the
201 * determination of these values, since that is non-constant across
202 * platforms.  This makes socket queueing behavior and performance
203 * not depend upon such differences.
204 */
205#define _SK_MEM_PACKETS		256
206#define _SK_MEM_OVERHEAD	(sizeof(struct sk_buff) + 256)
207#define SK_WMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
208#define SK_RMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
209
210/* Run time adjustable parameters. */
211__u32 sysctl_wmem_max __read_mostly = SK_WMEM_MAX;
212__u32 sysctl_rmem_max __read_mostly = SK_RMEM_MAX;
213__u32 sysctl_wmem_default __read_mostly = SK_WMEM_MAX;
214__u32 sysctl_rmem_default __read_mostly = SK_RMEM_MAX;
215
216/* Maximal space eaten by iovec or ancilliary data plus some space */
217int sysctl_optmem_max __read_mostly = sizeof(unsigned long)*(2*UIO_MAXIOV+512);
218EXPORT_SYMBOL(sysctl_optmem_max);
219
220static int sock_set_timeout(long *timeo_p, char __user *optval, int optlen)
221{
222	struct timeval tv;
223
224	if (optlen < sizeof(tv))
225		return -EINVAL;
226	if (copy_from_user(&tv, optval, sizeof(tv)))
227		return -EFAULT;
228	if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
229		return -EDOM;
230
231	if (tv.tv_sec < 0) {
232		static int warned __read_mostly;
233
234		*timeo_p = 0;
235		if (warned < 10 && net_ratelimit()) {
236			warned++;
237			printk(KERN_INFO "sock_set_timeout: `%s' (pid %d) "
238			       "tries to set negative timeout\n",
239				current->comm, task_pid_nr(current));
240		}
241		return 0;
242	}
243	*timeo_p = MAX_SCHEDULE_TIMEOUT;
244	if (tv.tv_sec == 0 && tv.tv_usec == 0)
245		return 0;
246	if (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT/HZ - 1))
247		*timeo_p = tv.tv_sec*HZ + (tv.tv_usec+(1000000/HZ-1))/(1000000/HZ);
248	return 0;
249}
250
251static void sock_warn_obsolete_bsdism(const char *name)
252{
253	static int warned;
254	static char warncomm[TASK_COMM_LEN];
255	if (strcmp(warncomm, current->comm) && warned < 5) {
256		strcpy(warncomm,  current->comm);
257		printk(KERN_WARNING "process `%s' is using obsolete "
258		       "%s SO_BSDCOMPAT\n", warncomm, name);
259		warned++;
260	}
261}
262
263static void sock_disable_timestamp(struct sock *sk, int flag)
264{
265	if (sock_flag(sk, flag)) {
266		sock_reset_flag(sk, flag);
267		if (!sock_flag(sk, SOCK_TIMESTAMP) &&
268		    !sock_flag(sk, SOCK_TIMESTAMPING_RX_SOFTWARE)) {
269			net_disable_timestamp();
270		}
271	}
272}
273
274
275int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
276{
277	int err;
278	int skb_len;
279	unsigned long flags;
280	struct sk_buff_head *list = &sk->sk_receive_queue;
281
282	/* Cast sk->rcvbuf to unsigned... It's pointless, but reduces
283	   number of warnings when compiling with -W --ANK
284	 */
285	if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
286	    (unsigned)sk->sk_rcvbuf) {
287		atomic_inc(&sk->sk_drops);
288		return -ENOMEM;
289	}
290
291	err = sk_filter(sk, skb);
292	if (err)
293		return err;
294
295	if (!sk_rmem_schedule(sk, skb->truesize)) {
296		atomic_inc(&sk->sk_drops);
297		return -ENOBUFS;
298	}
299
300	skb->dev = NULL;
301	skb_set_owner_r(skb, sk);
302
303	/* Cache the SKB length before we tack it onto the receive
304	 * queue.  Once it is added it no longer belongs to us and
305	 * may be freed by other threads of control pulling packets
306	 * from the queue.
307	 */
308	skb_len = skb->len;
309
310	spin_lock_irqsave(&list->lock, flags);
311	skb->dropcount = atomic_read(&sk->sk_drops);
312	__skb_queue_tail(list, skb);
313	spin_unlock_irqrestore(&list->lock, flags);
314
315	if (!sock_flag(sk, SOCK_DEAD))
316		sk->sk_data_ready(sk, skb_len);
317	return 0;
318}
319EXPORT_SYMBOL(sock_queue_rcv_skb);
320
321int sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested)
322{
323	int rc = NET_RX_SUCCESS;
324
325	if (sk_filter(sk, skb))
326		goto discard_and_relse;
327
328	skb->dev = NULL;
329
330	if (sk_rcvqueues_full(sk, skb)) {
331		atomic_inc(&sk->sk_drops);
332		goto discard_and_relse;
333	}
334	if (nested)
335		bh_lock_sock_nested(sk);
336	else
337		bh_lock_sock(sk);
338	if (!sock_owned_by_user(sk)) {
339		/*
340		 * trylock + unlock semantics:
341		 */
342		mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
343
344		rc = sk_backlog_rcv(sk, skb);
345
346		mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
347	} else if (sk_add_backlog(sk, skb)) {
348		bh_unlock_sock(sk);
349		atomic_inc(&sk->sk_drops);
350		goto discard_and_relse;
351	}
352
353	bh_unlock_sock(sk);
354out:
355	sock_put(sk);
356	return rc;
357discard_and_relse:
358	kfree_skb(skb);
359	goto out;
360}
361EXPORT_SYMBOL(sk_receive_skb);
362
363void sk_reset_txq(struct sock *sk)
364{
365	sk_tx_queue_clear(sk);
366}
367EXPORT_SYMBOL(sk_reset_txq);
368
369struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
370{
371	struct dst_entry *dst = __sk_dst_get(sk);
372
373	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
374		sk_tx_queue_clear(sk);
375		rcu_assign_pointer(sk->sk_dst_cache, NULL);
376		dst_release(dst);
377		return NULL;
378	}
379
380	return dst;
381}
382EXPORT_SYMBOL(__sk_dst_check);
383
384struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
385{
386	struct dst_entry *dst = sk_dst_get(sk);
387
388	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
389		sk_dst_reset(sk);
390		dst_release(dst);
391		return NULL;
392	}
393
394	return dst;
395}
396EXPORT_SYMBOL(sk_dst_check);
397
398static int sock_bindtodevice(struct sock *sk, char __user *optval, int optlen)
399{
400	int ret = -ENOPROTOOPT;
401#ifdef CONFIG_NETDEVICES
402	struct net *net = sock_net(sk);
403	char devname[IFNAMSIZ];
404	int index;
405
406	/* Sorry... */
407	ret = -EPERM;
408	if (!capable(CAP_NET_RAW))
409		goto out;
410
411	ret = -EINVAL;
412	if (optlen < 0)
413		goto out;
414
415	/* Bind this socket to a particular device like "eth0",
416	 * as specified in the passed interface name. If the
417	 * name is "" or the option length is zero the socket
418	 * is not bound.
419	 */
420	if (optlen > IFNAMSIZ - 1)
421		optlen = IFNAMSIZ - 1;
422	memset(devname, 0, sizeof(devname));
423
424	ret = -EFAULT;
425	if (copy_from_user(devname, optval, optlen))
426		goto out;
427
428	index = 0;
429	if (devname[0] != '\0') {
430		struct net_device *dev;
431
432		rcu_read_lock();
433		dev = dev_get_by_name_rcu(net, devname);
434		if (dev)
435			index = dev->ifindex;
436		rcu_read_unlock();
437		ret = -ENODEV;
438		if (!dev)
439			goto out;
440	}
441
442	lock_sock(sk);
443	sk->sk_bound_dev_if = index;
444	sk_dst_reset(sk);
445	release_sock(sk);
446
447	ret = 0;
448
449out:
450#endif
451
452	return ret;
453}
454
455static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool)
456{
457	if (valbool)
458		sock_set_flag(sk, bit);
459	else
460		sock_reset_flag(sk, bit);
461}
462
463/*
464 *	This is meant for all protocols to use and covers goings on
465 *	at the socket level. Everything here is generic.
466 */
467
468int sock_setsockopt(struct socket *sock, int level, int optname,
469		    char __user *optval, unsigned int optlen)
470{
471	struct sock *sk = sock->sk;
472	int val;
473	int valbool;
474	struct linger ling;
475	int ret = 0;
476
477	/*
478	 *	Options without arguments
479	 */
480
481	if (optname == SO_BINDTODEVICE)
482		return sock_bindtodevice(sk, optval, optlen);
483
484	if (optlen < sizeof(int))
485		return -EINVAL;
486
487	if (get_user(val, (int __user *)optval))
488		return -EFAULT;
489
490	valbool = val ? 1 : 0;
491
492	lock_sock(sk);
493
494	switch (optname) {
495	case SO_DEBUG:
496		if (val && !capable(CAP_NET_ADMIN))
497			ret = -EACCES;
498		else
499			sock_valbool_flag(sk, SOCK_DBG, valbool);
500		break;
501	case SO_REUSEADDR:
502		sk->sk_reuse = valbool;
503		break;
504	case SO_TYPE:
505	case SO_PROTOCOL:
506	case SO_DOMAIN:
507	case SO_ERROR:
508		ret = -ENOPROTOOPT;
509		break;
510	case SO_DONTROUTE:
511		sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
512		break;
513	case SO_BROADCAST:
514		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
515		break;
516	case SO_SNDBUF:
517		/* Don't error on this BSD doesn't and if you think
518		   about it this is right. Otherwise apps have to
519		   play 'guess the biggest size' games. RCVBUF/SNDBUF
520		   are treated in BSD as hints */
521
522		if (val > sysctl_wmem_max)
523			val = sysctl_wmem_max;
524set_sndbuf:
525		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
526		if ((val * 2) < SOCK_MIN_SNDBUF)
527			sk->sk_sndbuf = SOCK_MIN_SNDBUF;
528		else
529			sk->sk_sndbuf = val * 2;
530
531		/*
532		 *	Wake up sending tasks if we
533		 *	upped the value.
534		 */
535		sk->sk_write_space(sk);
536		break;
537
538	case SO_SNDBUFFORCE:
539		if (!capable(CAP_NET_ADMIN)) {
540			ret = -EPERM;
541			break;
542		}
543		goto set_sndbuf;
544
545	case SO_RCVBUF:
546		/* Don't error on this BSD doesn't and if you think
547		   about it this is right. Otherwise apps have to
548		   play 'guess the biggest size' games. RCVBUF/SNDBUF
549		   are treated in BSD as hints */
550
551		if (val > sysctl_rmem_max)
552			val = sysctl_rmem_max;
553set_rcvbuf:
554		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
555		/*
556		 * We double it on the way in to account for
557		 * "struct sk_buff" etc. overhead.   Applications
558		 * assume that the SO_RCVBUF setting they make will
559		 * allow that much actual data to be received on that
560		 * socket.
561		 *
562		 * Applications are unaware that "struct sk_buff" and
563		 * other overheads allocate from the receive buffer
564		 * during socket buffer allocation.
565		 *
566		 * And after considering the possible alternatives,
567		 * returning the value we actually used in getsockopt
568		 * is the most desirable behavior.
569		 */
570		if ((val * 2) < SOCK_MIN_RCVBUF)
571			sk->sk_rcvbuf = SOCK_MIN_RCVBUF;
572		else
573			sk->sk_rcvbuf = val * 2;
574		break;
575
576	case SO_RCVBUFFORCE:
577		if (!capable(CAP_NET_ADMIN)) {
578			ret = -EPERM;
579			break;
580		}
581		goto set_rcvbuf;
582
583	case SO_KEEPALIVE:
584#ifdef CONFIG_INET
585		if (sk->sk_protocol == IPPROTO_TCP)
586			tcp_set_keepalive(sk, valbool);
587#endif
588		sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
589		break;
590
591	case SO_OOBINLINE:
592		sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
593		break;
594
595	case SO_NO_CHECK:
596		sk->sk_no_check = valbool;
597		break;
598
599	case SO_PRIORITY:
600		if ((val >= 0 && val <= 6) || capable(CAP_NET_ADMIN))
601			sk->sk_priority = val;
602		else
603			ret = -EPERM;
604		break;
605
606	case SO_LINGER:
607		if (optlen < sizeof(ling)) {
608			ret = -EINVAL;	/* 1003.1g */
609			break;
610		}
611		if (copy_from_user(&ling, optval, sizeof(ling))) {
612			ret = -EFAULT;
613			break;
614		}
615		if (!ling.l_onoff)
616			sock_reset_flag(sk, SOCK_LINGER);
617		else {
618#if (BITS_PER_LONG == 32)
619			if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
620				sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
621			else
622#endif
623				sk->sk_lingertime = (unsigned int)ling.l_linger * HZ;
624			sock_set_flag(sk, SOCK_LINGER);
625		}
626		break;
627
628	case SO_BSDCOMPAT:
629		sock_warn_obsolete_bsdism("setsockopt");
630		break;
631
632	case SO_PASSCRED:
633		if (valbool)
634			set_bit(SOCK_PASSCRED, &sock->flags);
635		else
636			clear_bit(SOCK_PASSCRED, &sock->flags);
637		break;
638
639	case SO_TIMESTAMP:
640	case SO_TIMESTAMPNS:
641		if (valbool)  {
642			if (optname == SO_TIMESTAMP)
643				sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
644			else
645				sock_set_flag(sk, SOCK_RCVTSTAMPNS);
646			sock_set_flag(sk, SOCK_RCVTSTAMP);
647			sock_enable_timestamp(sk, SOCK_TIMESTAMP);
648		} else {
649			sock_reset_flag(sk, SOCK_RCVTSTAMP);
650			sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
651		}
652		break;
653
654	case SO_TIMESTAMPING:
655		if (val & ~SOF_TIMESTAMPING_MASK) {
656			ret = -EINVAL;
657			break;
658		}
659		sock_valbool_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE,
660				  val & SOF_TIMESTAMPING_TX_HARDWARE);
661		sock_valbool_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE,
662				  val & SOF_TIMESTAMPING_TX_SOFTWARE);
663		sock_valbool_flag(sk, SOCK_TIMESTAMPING_RX_HARDWARE,
664				  val & SOF_TIMESTAMPING_RX_HARDWARE);
665		if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
666			sock_enable_timestamp(sk,
667					      SOCK_TIMESTAMPING_RX_SOFTWARE);
668		else
669			sock_disable_timestamp(sk,
670					       SOCK_TIMESTAMPING_RX_SOFTWARE);
671		sock_valbool_flag(sk, SOCK_TIMESTAMPING_SOFTWARE,
672				  val & SOF_TIMESTAMPING_SOFTWARE);
673		sock_valbool_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE,
674				  val & SOF_TIMESTAMPING_SYS_HARDWARE);
675		sock_valbool_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE,
676				  val & SOF_TIMESTAMPING_RAW_HARDWARE);
677		break;
678
679	case SO_RCVLOWAT:
680		if (val < 0)
681			val = INT_MAX;
682		sk->sk_rcvlowat = val ? : 1;
683		break;
684
685	case SO_RCVTIMEO:
686		ret = sock_set_timeout(&sk->sk_rcvtimeo, optval, optlen);
687		break;
688
689	case SO_SNDTIMEO:
690		ret = sock_set_timeout(&sk->sk_sndtimeo, optval, optlen);
691		break;
692
693	case SO_ATTACH_FILTER:
694		ret = -EINVAL;
695		if (optlen == sizeof(struct sock_fprog)) {
696			struct sock_fprog fprog;
697
698			ret = -EFAULT;
699			if (copy_from_user(&fprog, optval, sizeof(fprog)))
700				break;
701
702			ret = sk_attach_filter(&fprog, sk);
703		}
704		break;
705
706	case SO_DETACH_FILTER:
707		ret = sk_detach_filter(sk);
708		break;
709
710	case SO_PASSSEC:
711		if (valbool)
712			set_bit(SOCK_PASSSEC, &sock->flags);
713		else
714			clear_bit(SOCK_PASSSEC, &sock->flags);
715		break;
716	case SO_MARK:
717		if (!capable(CAP_NET_ADMIN))
718			ret = -EPERM;
719		else
720			sk->sk_mark = val;
721		break;
722
723		/* We implement the SO_SNDLOWAT etc to
724		   not be settable (1003.1g 5.3) */
725	case SO_RXQ_OVFL:
726		if (valbool)
727			sock_set_flag(sk, SOCK_RXQ_OVFL);
728		else
729			sock_reset_flag(sk, SOCK_RXQ_OVFL);
730		break;
731	default:
732		ret = -ENOPROTOOPT;
733		break;
734	}
735	release_sock(sk);
736	return ret;
737}
738EXPORT_SYMBOL(sock_setsockopt);
739
740
741int sock_getsockopt(struct socket *sock, int level, int optname,
742		    char __user *optval, int __user *optlen)
743{
744	struct sock *sk = sock->sk;
745
746	union {
747		int val;
748		struct linger ling;
749		struct timeval tm;
750	} v;
751
752	int lv = sizeof(int);
753	int len;
754
755	if (get_user(len, optlen))
756		return -EFAULT;
757	if (len < 0)
758		return -EINVAL;
759
760	memset(&v, 0, sizeof(v));
761
762	switch (optname) {
763	case SO_DEBUG:
764		v.val = sock_flag(sk, SOCK_DBG);
765		break;
766
767	case SO_DONTROUTE:
768		v.val = sock_flag(sk, SOCK_LOCALROUTE);
769		break;
770
771	case SO_BROADCAST:
772		v.val = !!sock_flag(sk, SOCK_BROADCAST);
773		break;
774
775	case SO_SNDBUF:
776		v.val = sk->sk_sndbuf;
777		break;
778
779	case SO_RCVBUF:
780		v.val = sk->sk_rcvbuf;
781		break;
782
783	case SO_REUSEADDR:
784		v.val = sk->sk_reuse;
785		break;
786
787	case SO_KEEPALIVE:
788		v.val = !!sock_flag(sk, SOCK_KEEPOPEN);
789		break;
790
791	case SO_TYPE:
792		v.val = sk->sk_type;
793		break;
794
795	case SO_PROTOCOL:
796		v.val = sk->sk_protocol;
797		break;
798
799	case SO_DOMAIN:
800		v.val = sk->sk_family;
801		break;
802
803	case SO_ERROR:
804		v.val = -sock_error(sk);
805		if (v.val == 0)
806			v.val = xchg(&sk->sk_err_soft, 0);
807		break;
808
809	case SO_OOBINLINE:
810		v.val = !!sock_flag(sk, SOCK_URGINLINE);
811		break;
812
813	case SO_NO_CHECK:
814		v.val = sk->sk_no_check;
815		break;
816
817	case SO_PRIORITY:
818		v.val = sk->sk_priority;
819		break;
820
821	case SO_LINGER:
822		lv		= sizeof(v.ling);
823		v.ling.l_onoff	= !!sock_flag(sk, SOCK_LINGER);
824		v.ling.l_linger	= sk->sk_lingertime / HZ;
825		break;
826
827	case SO_BSDCOMPAT:
828		sock_warn_obsolete_bsdism("getsockopt");
829		break;
830
831	case SO_TIMESTAMP:
832		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
833				!sock_flag(sk, SOCK_RCVTSTAMPNS);
834		break;
835
836	case SO_TIMESTAMPNS:
837		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS);
838		break;
839
840	case SO_TIMESTAMPING:
841		v.val = 0;
842		if (sock_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE))
843			v.val |= SOF_TIMESTAMPING_TX_HARDWARE;
844		if (sock_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE))
845			v.val |= SOF_TIMESTAMPING_TX_SOFTWARE;
846		if (sock_flag(sk, SOCK_TIMESTAMPING_RX_HARDWARE))
847			v.val |= SOF_TIMESTAMPING_RX_HARDWARE;
848		if (sock_flag(sk, SOCK_TIMESTAMPING_RX_SOFTWARE))
849			v.val |= SOF_TIMESTAMPING_RX_SOFTWARE;
850		if (sock_flag(sk, SOCK_TIMESTAMPING_SOFTWARE))
851			v.val |= SOF_TIMESTAMPING_SOFTWARE;
852		if (sock_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE))
853			v.val |= SOF_TIMESTAMPING_SYS_HARDWARE;
854		if (sock_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE))
855			v.val |= SOF_TIMESTAMPING_RAW_HARDWARE;
856		break;
857
858	case SO_RCVTIMEO:
859		lv = sizeof(struct timeval);
860		if (sk->sk_rcvtimeo == MAX_SCHEDULE_TIMEOUT) {
861			v.tm.tv_sec = 0;
862			v.tm.tv_usec = 0;
863		} else {
864			v.tm.tv_sec = sk->sk_rcvtimeo / HZ;
865			v.tm.tv_usec = ((sk->sk_rcvtimeo % HZ) * 1000000) / HZ;
866		}
867		break;
868
869	case SO_SNDTIMEO:
870		lv = sizeof(struct timeval);
871		if (sk->sk_sndtimeo == MAX_SCHEDULE_TIMEOUT) {
872			v.tm.tv_sec = 0;
873			v.tm.tv_usec = 0;
874		} else {
875			v.tm.tv_sec = sk->sk_sndtimeo / HZ;
876			v.tm.tv_usec = ((sk->sk_sndtimeo % HZ) * 1000000) / HZ;
877		}
878		break;
879
880	case SO_RCVLOWAT:
881		v.val = sk->sk_rcvlowat;
882		break;
883
884	case SO_SNDLOWAT:
885		v.val = 1;
886		break;
887
888	case SO_PASSCRED:
889		v.val = test_bit(SOCK_PASSCRED, &sock->flags) ? 1 : 0;
890		break;
891
892	case SO_PEERCRED:
893		if (len > sizeof(sk->sk_peercred))
894			len = sizeof(sk->sk_peercred);
895		if (copy_to_user(optval, &sk->sk_peercred, len))
896			return -EFAULT;
897		goto lenout;
898
899	case SO_PEERNAME:
900	{
901		char address[128];
902
903		if (sock->ops->getname(sock, (struct sockaddr *)address, &lv, 2))
904			return -ENOTCONN;
905		if (lv < len)
906			return -EINVAL;
907		if (copy_to_user(optval, address, len))
908			return -EFAULT;
909		goto lenout;
910	}
911
912	/* Dubious BSD thing... Probably nobody even uses it, but
913	 * the UNIX standard wants it for whatever reason... -DaveM
914	 */
915	case SO_ACCEPTCONN:
916		v.val = sk->sk_state == TCP_LISTEN;
917		break;
918
919	case SO_PASSSEC:
920		v.val = test_bit(SOCK_PASSSEC, &sock->flags) ? 1 : 0;
921		break;
922
923	case SO_PEERSEC:
924		return security_socket_getpeersec_stream(sock, optval, optlen, len);
925
926	case SO_MARK:
927		v.val = sk->sk_mark;
928		break;
929
930	case SO_RXQ_OVFL:
931		v.val = !!sock_flag(sk, SOCK_RXQ_OVFL);
932		break;
933
934	default:
935		return -ENOPROTOOPT;
936	}
937
938	if (len > lv)
939		len = lv;
940	if (copy_to_user(optval, &v, len))
941		return -EFAULT;
942lenout:
943	if (put_user(len, optlen))
944		return -EFAULT;
945	return 0;
946}
947
948/*
949 * Initialize an sk_lock.
950 *
951 * (We also register the sk_lock with the lock validator.)
952 */
953static inline void sock_lock_init(struct sock *sk)
954{
955	sock_lock_init_class_and_name(sk,
956			af_family_slock_key_strings[sk->sk_family],
957			af_family_slock_keys + sk->sk_family,
958			af_family_key_strings[sk->sk_family],
959			af_family_keys + sk->sk_family);
960}
961
962/*
963 * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
964 * even temporarly, because of RCU lookups. sk_node should also be left as is.
965 */
966static void sock_copy(struct sock *nsk, const struct sock *osk)
967{
968#ifdef CONFIG_SECURITY_NETWORK
969	void *sptr = nsk->sk_security;
970#endif
971	BUILD_BUG_ON(offsetof(struct sock, sk_copy_start) !=
972		     sizeof(osk->sk_node) + sizeof(osk->sk_refcnt) +
973		     sizeof(osk->sk_tx_queue_mapping));
974	memcpy(&nsk->sk_copy_start, &osk->sk_copy_start,
975	       osk->sk_prot->obj_size - offsetof(struct sock, sk_copy_start));
976#ifdef CONFIG_SECURITY_NETWORK
977	nsk->sk_security = sptr;
978	security_sk_clone(osk, nsk);
979#endif
980}
981
982static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
983		int family)
984{
985	struct sock *sk;
986	struct kmem_cache *slab;
987
988	slab = prot->slab;
989	if (slab != NULL) {
990		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
991		if (!sk)
992			return sk;
993		if (priority & __GFP_ZERO) {
994			/*
995			 * caches using SLAB_DESTROY_BY_RCU should let
996			 * sk_node.next un-modified. Special care is taken
997			 * when initializing object to zero.
998			 */
999			if (offsetof(struct sock, sk_node.next) != 0)
1000				memset(sk, 0, offsetof(struct sock, sk_node.next));
1001			memset(&sk->sk_node.pprev, 0,
1002			       prot->obj_size - offsetof(struct sock,
1003							 sk_node.pprev));
1004		}
1005	}
1006	else
1007		sk = kmalloc(prot->obj_size, priority);
1008
1009	if (sk != NULL) {
1010		kmemcheck_annotate_bitfield(sk, flags);
1011
1012		if (security_sk_alloc(sk, family, priority))
1013			goto out_free;
1014
1015		if (!try_module_get(prot->owner))
1016			goto out_free_sec;
1017		sk_tx_queue_clear(sk);
1018	}
1019
1020	return sk;
1021
1022out_free_sec:
1023	security_sk_free(sk);
1024out_free:
1025	if (slab != NULL)
1026		kmem_cache_free(slab, sk);
1027	else
1028		kfree(sk);
1029	return NULL;
1030}
1031
1032static void sk_prot_free(struct proto *prot, struct sock *sk)
1033{
1034	struct kmem_cache *slab;
1035	struct module *owner;
1036
1037	owner = prot->owner;
1038	slab = prot->slab;
1039
1040	security_sk_free(sk);
1041	if (slab != NULL)
1042		kmem_cache_free(slab, sk);
1043	else
1044		kfree(sk);
1045	module_put(owner);
1046}
1047
1048/**
1049 *	sk_alloc - All socket objects are allocated here
1050 *	@net: the applicable net namespace
1051 *	@family: protocol family
1052 *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1053 *	@prot: struct proto associated with this new sock instance
1054 */
1055struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1056		      struct proto *prot)
1057{
1058	struct sock *sk;
1059
1060	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
1061	if (sk) {
1062		sk->sk_family = family;
1063		/*
1064		 * See comment in struct sock definition to understand
1065		 * why we need sk_prot_creator -acme
1066		 */
1067		sk->sk_prot = sk->sk_prot_creator = prot;
1068		sock_lock_init(sk);
1069		sock_net_set(sk, get_net(net));
1070		atomic_set(&sk->sk_wmem_alloc, 1);
1071	}
1072
1073	return sk;
1074}
1075EXPORT_SYMBOL(sk_alloc);
1076
1077static void __sk_free(struct sock *sk)
1078{
1079	struct sk_filter *filter;
1080
1081	if (sk->sk_destruct)
1082		sk->sk_destruct(sk);
1083
1084	filter = rcu_dereference_check(sk->sk_filter,
1085				       atomic_read(&sk->sk_wmem_alloc) == 0);
1086	if (filter) {
1087		sk_filter_uncharge(sk, filter);
1088		rcu_assign_pointer(sk->sk_filter, NULL);
1089	}
1090
1091	sock_disable_timestamp(sk, SOCK_TIMESTAMP);
1092	sock_disable_timestamp(sk, SOCK_TIMESTAMPING_RX_SOFTWARE);
1093
1094	if (atomic_read(&sk->sk_omem_alloc))
1095		printk(KERN_DEBUG "%s: optmem leakage (%d bytes) detected.\n",
1096		       __func__, atomic_read(&sk->sk_omem_alloc));
1097
1098	put_net(sock_net(sk));
1099	sk_prot_free(sk->sk_prot_creator, sk);
1100}
1101
1102void sk_free(struct sock *sk)
1103{
1104	/*
1105	 * We substract one from sk_wmem_alloc and can know if
1106	 * some packets are still in some tx queue.
1107	 * If not null, sock_wfree() will call __sk_free(sk) later
1108	 */
1109	if (atomic_dec_and_test(&sk->sk_wmem_alloc))
1110		__sk_free(sk);
1111}
1112EXPORT_SYMBOL(sk_free);
1113
1114/*
1115 * Last sock_put should drop referrence to sk->sk_net. It has already
1116 * been dropped in sk_change_net. Taking referrence to stopping namespace
1117 * is not an option.
1118 * Take referrence to a socket to remove it from hash _alive_ and after that
1119 * destroy it in the context of init_net.
1120 */
1121void sk_release_kernel(struct sock *sk)
1122{
1123	if (sk == NULL || sk->sk_socket == NULL)
1124		return;
1125
1126	sock_hold(sk);
1127	sock_release(sk->sk_socket);
1128	release_net(sock_net(sk));
1129	sock_net_set(sk, get_net(&init_net));
1130	sock_put(sk);
1131}
1132EXPORT_SYMBOL(sk_release_kernel);
1133
1134struct sock *sk_clone(const struct sock *sk, const gfp_t priority)
1135{
1136	struct sock *newsk;
1137
1138	newsk = sk_prot_alloc(sk->sk_prot, priority, sk->sk_family);
1139	if (newsk != NULL) {
1140		struct sk_filter *filter;
1141
1142		sock_copy(newsk, sk);
1143
1144		/* SANITY */
1145		get_net(sock_net(newsk));
1146		sk_node_init(&newsk->sk_node);
1147		sock_lock_init(newsk);
1148		bh_lock_sock(newsk);
1149		newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
1150		newsk->sk_backlog.len = 0;
1151
1152		atomic_set(&newsk->sk_rmem_alloc, 0);
1153		/*
1154		 * sk_wmem_alloc set to one (see sk_free() and sock_wfree())
1155		 */
1156		atomic_set(&newsk->sk_wmem_alloc, 1);
1157		atomic_set(&newsk->sk_omem_alloc, 0);
1158		skb_queue_head_init(&newsk->sk_receive_queue);
1159		skb_queue_head_init(&newsk->sk_write_queue);
1160#ifdef CONFIG_NET_DMA
1161		skb_queue_head_init(&newsk->sk_async_wait_queue);
1162#endif
1163
1164		spin_lock_init(&newsk->sk_dst_lock);
1165		rwlock_init(&newsk->sk_callback_lock);
1166		lockdep_set_class_and_name(&newsk->sk_callback_lock,
1167				af_callback_keys + newsk->sk_family,
1168				af_family_clock_key_strings[newsk->sk_family]);
1169
1170		newsk->sk_dst_cache	= NULL;
1171		newsk->sk_wmem_queued	= 0;
1172		newsk->sk_forward_alloc = 0;
1173		newsk->sk_send_head	= NULL;
1174		newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
1175
1176		sock_reset_flag(newsk, SOCK_DONE);
1177		skb_queue_head_init(&newsk->sk_error_queue);
1178
1179		filter = newsk->sk_filter;
1180		if (filter != NULL)
1181			sk_filter_charge(newsk, filter);
1182
1183		if (unlikely(xfrm_sk_clone_policy(newsk))) {
1184			/* It is still raw copy of parent, so invalidate
1185			 * destructor and make plain sk_free() */
1186			newsk->sk_destruct = NULL;
1187			sk_free(newsk);
1188			newsk = NULL;
1189			goto out;
1190		}
1191
1192		newsk->sk_err	   = 0;
1193		newsk->sk_priority = 0;
1194		/*
1195		 * Before updating sk_refcnt, we must commit prior changes to memory
1196		 * (Documentation/RCU/rculist_nulls.txt for details)
1197		 */
1198		smp_wmb();
1199		atomic_set(&newsk->sk_refcnt, 2);
1200
1201		/*
1202		 * Increment the counter in the same struct proto as the master
1203		 * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
1204		 * is the same as sk->sk_prot->socks, as this field was copied
1205		 * with memcpy).
1206		 *
1207		 * This _changes_ the previous behaviour, where
1208		 * tcp_create_openreq_child always was incrementing the
1209		 * equivalent to tcp_prot->socks (inet_sock_nr), so this have
1210		 * to be taken into account in all callers. -acme
1211		 */
1212		sk_refcnt_debug_inc(newsk);
1213		sk_set_socket(newsk, NULL);
1214		newsk->sk_wq = NULL;
1215
1216		if (newsk->sk_prot->sockets_allocated)
1217			percpu_counter_inc(newsk->sk_prot->sockets_allocated);
1218
1219		if (sock_flag(newsk, SOCK_TIMESTAMP) ||
1220		    sock_flag(newsk, SOCK_TIMESTAMPING_RX_SOFTWARE))
1221			net_enable_timestamp();
1222	}
1223out:
1224	return newsk;
1225}
1226EXPORT_SYMBOL_GPL(sk_clone);
1227
1228void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
1229{
1230	__sk_dst_set(sk, dst);
1231	sk->sk_route_caps = dst->dev->features;
1232	if (sk->sk_route_caps & NETIF_F_GSO)
1233		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
1234	if (sk_can_gso(sk)) {
1235		if (dst->header_len) {
1236			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
1237		} else {
1238			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
1239			sk->sk_gso_max_size = dst->dev->gso_max_size;
1240		}
1241	}
1242}
1243EXPORT_SYMBOL_GPL(sk_setup_caps);
1244
1245void __init sk_init(void)
1246{
1247	if (totalram_pages <= 4096) {
1248		sysctl_wmem_max = 32767;
1249		sysctl_rmem_max = 32767;
1250		sysctl_wmem_default = 32767;
1251		sysctl_rmem_default = 32767;
1252	} else if (totalram_pages >= 131072) {
1253		sysctl_wmem_max = 131071;
1254		sysctl_rmem_max = 131071;
1255	}
1256}
1257
1258/*
1259 *	Simple resource managers for sockets.
1260 */
1261
1262
1263/*
1264 * Write buffer destructor automatically called from kfree_skb.
1265 */
1266void sock_wfree(struct sk_buff *skb)
1267{
1268	struct sock *sk = skb->sk;
1269	unsigned int len = skb->truesize;
1270
1271	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
1272		/*
1273		 * Keep a reference on sk_wmem_alloc, this will be released
1274		 * after sk_write_space() call
1275		 */
1276		atomic_sub(len - 1, &sk->sk_wmem_alloc);
1277		sk->sk_write_space(sk);
1278		len = 1;
1279	}
1280	/*
1281	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
1282	 * could not do because of in-flight packets
1283	 */
1284	if (atomic_sub_and_test(len, &sk->sk_wmem_alloc))
1285		__sk_free(sk);
1286}
1287EXPORT_SYMBOL(sock_wfree);
1288
1289/*
1290 * Read buffer destructor automatically called from kfree_skb.
1291 */
1292void sock_rfree(struct sk_buff *skb)
1293{
1294	struct sock *sk = skb->sk;
1295
1296	atomic_sub(skb->truesize, &sk->sk_rmem_alloc);
1297	sk_mem_uncharge(skb->sk, skb->truesize);
1298}
1299EXPORT_SYMBOL(sock_rfree);
1300
1301
1302int sock_i_uid(struct sock *sk)
1303{
1304	int uid;
1305
1306	read_lock(&sk->sk_callback_lock);
1307	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : 0;
1308	read_unlock(&sk->sk_callback_lock);
1309	return uid;
1310}
1311EXPORT_SYMBOL(sock_i_uid);
1312
1313unsigned long sock_i_ino(struct sock *sk)
1314{
1315	unsigned long ino;
1316
1317	read_lock(&sk->sk_callback_lock);
1318	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
1319	read_unlock(&sk->sk_callback_lock);
1320	return ino;
1321}
1322EXPORT_SYMBOL(sock_i_ino);
1323
1324/*
1325 * Allocate a skb from the socket's send buffer.
1326 */
1327struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1328			     gfp_t priority)
1329{
1330	if (force || atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1331		struct sk_buff *skb = alloc_skb(size, priority);
1332		if (skb) {
1333			skb_set_owner_w(skb, sk);
1334			return skb;
1335		}
1336	}
1337	return NULL;
1338}
1339EXPORT_SYMBOL(sock_wmalloc);
1340
1341/*
1342 * Allocate a skb from the socket's receive buffer.
1343 */
1344struct sk_buff *sock_rmalloc(struct sock *sk, unsigned long size, int force,
1345			     gfp_t priority)
1346{
1347	if (force || atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
1348		struct sk_buff *skb = alloc_skb(size, priority);
1349		if (skb) {
1350			skb_set_owner_r(skb, sk);
1351			return skb;
1352		}
1353	}
1354	return NULL;
1355}
1356
1357/*
1358 * Allocate a memory block from the socket's option memory buffer.
1359 */
1360void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
1361{
1362	if ((unsigned)size <= sysctl_optmem_max &&
1363	    atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
1364		void *mem;
1365		/* First do the add, to avoid the race if kmalloc
1366		 * might sleep.
1367		 */
1368		atomic_add(size, &sk->sk_omem_alloc);
1369		mem = kmalloc(size, priority);
1370		if (mem)
1371			return mem;
1372		atomic_sub(size, &sk->sk_omem_alloc);
1373	}
1374	return NULL;
1375}
1376EXPORT_SYMBOL(sock_kmalloc);
1377
1378/*
1379 * Free an option memory block.
1380 */
1381void sock_kfree_s(struct sock *sk, void *mem, int size)
1382{
1383	kfree(mem);
1384	atomic_sub(size, &sk->sk_omem_alloc);
1385}
1386EXPORT_SYMBOL(sock_kfree_s);
1387
1388/* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
1389   I think, these locks should be removed for datagram sockets.
1390 */
1391static long sock_wait_for_wmem(struct sock *sk, long timeo)
1392{
1393	DEFINE_WAIT(wait);
1394
1395	clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1396	for (;;) {
1397		if (!timeo)
1398			break;
1399		if (signal_pending(current))
1400			break;
1401		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1402		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1403		if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf)
1404			break;
1405		if (sk->sk_shutdown & SEND_SHUTDOWN)
1406			break;
1407		if (sk->sk_err)
1408			break;
1409		timeo = schedule_timeout(timeo);
1410	}
1411	finish_wait(sk_sleep(sk), &wait);
1412	return timeo;
1413}
1414
1415
1416/*
1417 *	Generic send/receive buffer handlers
1418 */
1419
1420struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1421				     unsigned long data_len, int noblock,
1422				     int *errcode)
1423{
1424	struct sk_buff *skb;
1425	gfp_t gfp_mask;
1426	long timeo;
1427	int err;
1428
1429	gfp_mask = sk->sk_allocation;
1430	if (gfp_mask & __GFP_WAIT)
1431		gfp_mask |= __GFP_REPEAT;
1432
1433	timeo = sock_sndtimeo(sk, noblock);
1434	while (1) {
1435		err = sock_error(sk);
1436		if (err != 0)
1437			goto failure;
1438
1439		err = -EPIPE;
1440		if (sk->sk_shutdown & SEND_SHUTDOWN)
1441			goto failure;
1442
1443		if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1444			skb = alloc_skb(header_len, gfp_mask);
1445			if (skb) {
1446				int npages;
1447				int i;
1448
1449				/* No pages, we're done... */
1450				if (!data_len)
1451					break;
1452
1453				npages = (data_len + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
1454				skb->truesize += data_len;
1455				skb_shinfo(skb)->nr_frags = npages;
1456				for (i = 0; i < npages; i++) {
1457					struct page *page;
1458					skb_frag_t *frag;
1459
1460					page = alloc_pages(sk->sk_allocation, 0);
1461					if (!page) {
1462						err = -ENOBUFS;
1463						skb_shinfo(skb)->nr_frags = i;
1464						kfree_skb(skb);
1465						goto failure;
1466					}
1467
1468					frag = &skb_shinfo(skb)->frags[i];
1469					frag->page = page;
1470					frag->page_offset = 0;
1471					frag->size = (data_len >= PAGE_SIZE ?
1472						      PAGE_SIZE :
1473						      data_len);
1474					data_len -= PAGE_SIZE;
1475				}
1476
1477				/* Full success... */
1478				break;
1479			}
1480			err = -ENOBUFS;
1481			goto failure;
1482		}
1483		set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1484		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1485		err = -EAGAIN;
1486		if (!timeo)
1487			goto failure;
1488		if (signal_pending(current))
1489			goto interrupted;
1490		timeo = sock_wait_for_wmem(sk, timeo);
1491	}
1492
1493	skb_set_owner_w(skb, sk);
1494	return skb;
1495
1496interrupted:
1497	err = sock_intr_errno(timeo);
1498failure:
1499	*errcode = err;
1500	return NULL;
1501}
1502EXPORT_SYMBOL(sock_alloc_send_pskb);
1503
1504struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1505				    int noblock, int *errcode)
1506{
1507	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode);
1508}
1509EXPORT_SYMBOL(sock_alloc_send_skb);
1510
1511static void __lock_sock(struct sock *sk)
1512{
1513	DEFINE_WAIT(wait);
1514
1515	for (;;) {
1516		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
1517					TASK_UNINTERRUPTIBLE);
1518		spin_unlock_bh(&sk->sk_lock.slock);
1519		schedule();
1520		spin_lock_bh(&sk->sk_lock.slock);
1521		if (!sock_owned_by_user(sk))
1522			break;
1523	}
1524	finish_wait(&sk->sk_lock.wq, &wait);
1525}
1526
1527static void __release_sock(struct sock *sk)
1528{
1529	struct sk_buff *skb = sk->sk_backlog.head;
1530
1531	do {
1532		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
1533		bh_unlock_sock(sk);
1534
1535		do {
1536			struct sk_buff *next = skb->next;
1537
1538			skb->next = NULL;
1539			sk_backlog_rcv(sk, skb);
1540
1541			/*
1542			 * We are in process context here with softirqs
1543			 * disabled, use cond_resched_softirq() to preempt.
1544			 * This is safe to do because we've taken the backlog
1545			 * queue private:
1546			 */
1547			cond_resched_softirq();
1548
1549			skb = next;
1550		} while (skb != NULL);
1551
1552		bh_lock_sock(sk);
1553	} while ((skb = sk->sk_backlog.head) != NULL);
1554
1555	/*
1556	 * Doing the zeroing here guarantee we can not loop forever
1557	 * while a wild producer attempts to flood us.
1558	 */
1559	sk->sk_backlog.len = 0;
1560}
1561
1562/**
1563 * sk_wait_data - wait for data to arrive at sk_receive_queue
1564 * @sk:    sock to wait on
1565 * @timeo: for how long
1566 *
1567 * Now socket state including sk->sk_err is changed only under lock,
1568 * hence we may omit checks after joining wait queue.
1569 * We check receive queue before schedule() only as optimization;
1570 * it is very likely that release_sock() added new data.
1571 */
1572int sk_wait_data(struct sock *sk, long *timeo)
1573{
1574	int rc;
1575	DEFINE_WAIT(wait);
1576
1577	prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1578	set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1579	rc = sk_wait_event(sk, timeo, !skb_queue_empty(&sk->sk_receive_queue));
1580	clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1581	finish_wait(sk_sleep(sk), &wait);
1582	return rc;
1583}
1584EXPORT_SYMBOL(sk_wait_data);
1585
1586/**
1587 *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
1588 *	@sk: socket
1589 *	@size: memory size to allocate
1590 *	@kind: allocation type
1591 *
1592 *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
1593 *	rmem allocation. This function assumes that protocols which have
1594 *	memory_pressure use sk_wmem_queued as write buffer accounting.
1595 */
1596int __sk_mem_schedule(struct sock *sk, int size, int kind)
1597{
1598	struct proto *prot = sk->sk_prot;
1599	int amt = sk_mem_pages(size);
1600	int allocated;
1601
1602	sk->sk_forward_alloc += amt * SK_MEM_QUANTUM;
1603	allocated = atomic_add_return(amt, prot->memory_allocated);
1604
1605	/* Under limit. */
1606	if (allocated <= prot->sysctl_mem[0]) {
1607		if (prot->memory_pressure && *prot->memory_pressure)
1608			*prot->memory_pressure = 0;
1609		return 1;
1610	}
1611
1612	/* Under pressure. */
1613	if (allocated > prot->sysctl_mem[1])
1614		if (prot->enter_memory_pressure)
1615			prot->enter_memory_pressure(sk);
1616
1617	/* Over hard limit. */
1618	if (allocated > prot->sysctl_mem[2])
1619		goto suppress_allocation;
1620
1621	/* guarantee minimum buffer size under pressure */
1622	if (kind == SK_MEM_RECV) {
1623		if (atomic_read(&sk->sk_rmem_alloc) < prot->sysctl_rmem[0])
1624			return 1;
1625	} else { /* SK_MEM_SEND */
1626		if (sk->sk_type == SOCK_STREAM) {
1627			if (sk->sk_wmem_queued < prot->sysctl_wmem[0])
1628				return 1;
1629		} else if (atomic_read(&sk->sk_wmem_alloc) <
1630			   prot->sysctl_wmem[0])
1631				return 1;
1632	}
1633
1634	if (prot->memory_pressure) {
1635		int alloc;
1636
1637		if (!*prot->memory_pressure)
1638			return 1;
1639		alloc = percpu_counter_read_positive(prot->sockets_allocated);
1640		if (prot->sysctl_mem[2] > alloc *
1641		    sk_mem_pages(sk->sk_wmem_queued +
1642				 atomic_read(&sk->sk_rmem_alloc) +
1643				 sk->sk_forward_alloc))
1644			return 1;
1645	}
1646
1647suppress_allocation:
1648
1649	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
1650		sk_stream_moderate_sndbuf(sk);
1651
1652		/* Fail only if socket is _under_ its sndbuf.
1653		 * In this case we cannot block, so that we have to fail.
1654		 */
1655		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
1656			return 1;
1657	}
1658
1659	/* Alas. Undo changes. */
1660	sk->sk_forward_alloc -= amt * SK_MEM_QUANTUM;
1661	atomic_sub(amt, prot->memory_allocated);
1662	return 0;
1663}
1664EXPORT_SYMBOL(__sk_mem_schedule);
1665
1666/**
1667 *	__sk_reclaim - reclaim memory_allocated
1668 *	@sk: socket
1669 */
1670void __sk_mem_reclaim(struct sock *sk)
1671{
1672	struct proto *prot = sk->sk_prot;
1673
1674	atomic_sub(sk->sk_forward_alloc >> SK_MEM_QUANTUM_SHIFT,
1675		   prot->memory_allocated);
1676	sk->sk_forward_alloc &= SK_MEM_QUANTUM - 1;
1677
1678	if (prot->memory_pressure && *prot->memory_pressure &&
1679	    (atomic_read(prot->memory_allocated) < prot->sysctl_mem[0]))
1680		*prot->memory_pressure = 0;
1681}
1682EXPORT_SYMBOL(__sk_mem_reclaim);
1683
1684
1685/*
1686 * Set of default routines for initialising struct proto_ops when
1687 * the protocol does not support a particular function. In certain
1688 * cases where it makes no sense for a protocol to have a "do nothing"
1689 * function, some default processing is provided.
1690 */
1691
1692int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
1693{
1694	return -EOPNOTSUPP;
1695}
1696EXPORT_SYMBOL(sock_no_bind);
1697
1698int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
1699		    int len, int flags)
1700{
1701	return -EOPNOTSUPP;
1702}
1703EXPORT_SYMBOL(sock_no_connect);
1704
1705int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
1706{
1707	return -EOPNOTSUPP;
1708}
1709EXPORT_SYMBOL(sock_no_socketpair);
1710
1711int sock_no_accept(struct socket *sock, struct socket *newsock, int flags)
1712{
1713	return -EOPNOTSUPP;
1714}
1715EXPORT_SYMBOL(sock_no_accept);
1716
1717int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
1718		    int *len, int peer)
1719{
1720	return -EOPNOTSUPP;
1721}
1722EXPORT_SYMBOL(sock_no_getname);
1723
1724unsigned int sock_no_poll(struct file *file, struct socket *sock, poll_table *pt)
1725{
1726	return 0;
1727}
1728EXPORT_SYMBOL(sock_no_poll);
1729
1730int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1731{
1732	return -EOPNOTSUPP;
1733}
1734EXPORT_SYMBOL(sock_no_ioctl);
1735
1736int sock_no_listen(struct socket *sock, int backlog)
1737{
1738	return -EOPNOTSUPP;
1739}
1740EXPORT_SYMBOL(sock_no_listen);
1741
1742int sock_no_shutdown(struct socket *sock, int how)
1743{
1744	return -EOPNOTSUPP;
1745}
1746EXPORT_SYMBOL(sock_no_shutdown);
1747
1748int sock_no_setsockopt(struct socket *sock, int level, int optname,
1749		    char __user *optval, unsigned int optlen)
1750{
1751	return -EOPNOTSUPP;
1752}
1753EXPORT_SYMBOL(sock_no_setsockopt);
1754
1755int sock_no_getsockopt(struct socket *sock, int level, int optname,
1756		    char __user *optval, int __user *optlen)
1757{
1758	return -EOPNOTSUPP;
1759}
1760EXPORT_SYMBOL(sock_no_getsockopt);
1761
1762int sock_no_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
1763		    size_t len)
1764{
1765	return -EOPNOTSUPP;
1766}
1767EXPORT_SYMBOL(sock_no_sendmsg);
1768
1769int sock_no_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
1770		    size_t len, int flags)
1771{
1772	return -EOPNOTSUPP;
1773}
1774EXPORT_SYMBOL(sock_no_recvmsg);
1775
1776int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
1777{
1778	/* Mirror missing mmap method error code */
1779	return -ENODEV;
1780}
1781EXPORT_SYMBOL(sock_no_mmap);
1782
1783ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
1784{
1785	ssize_t res;
1786	struct msghdr msg = {.msg_flags = flags};
1787	struct kvec iov;
1788	char *kaddr = kmap(page);
1789	iov.iov_base = kaddr + offset;
1790	iov.iov_len = size;
1791	res = kernel_sendmsg(sock, &msg, &iov, 1, size);
1792	kunmap(page);
1793	return res;
1794}
1795EXPORT_SYMBOL(sock_no_sendpage);
1796
1797/*
1798 *	Default Socket Callbacks
1799 */
1800
1801static void sock_def_wakeup(struct sock *sk)
1802{
1803	struct socket_wq *wq;
1804
1805	rcu_read_lock();
1806	wq = rcu_dereference(sk->sk_wq);
1807	if (wq_has_sleeper(wq))
1808		wake_up_interruptible_all(&wq->wait);
1809	rcu_read_unlock();
1810}
1811
1812static void sock_def_error_report(struct sock *sk)
1813{
1814	struct socket_wq *wq;
1815
1816	rcu_read_lock();
1817	wq = rcu_dereference(sk->sk_wq);
1818	if (wq_has_sleeper(wq))
1819		wake_up_interruptible_poll(&wq->wait, POLLERR);
1820	sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
1821	rcu_read_unlock();
1822}
1823
1824static void sock_def_readable(struct sock *sk, int len)
1825{
1826	struct socket_wq *wq;
1827
1828	rcu_read_lock();
1829	wq = rcu_dereference(sk->sk_wq);
1830	if (wq_has_sleeper(wq))
1831		wake_up_interruptible_sync_poll(&wq->wait, POLLIN |
1832						POLLRDNORM | POLLRDBAND);
1833	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
1834	rcu_read_unlock();
1835}
1836
1837static void sock_def_write_space(struct sock *sk)
1838{
1839	struct socket_wq *wq;
1840
1841	rcu_read_lock();
1842
1843	/* Do not wake up a writer until he can make "significant"
1844	 * progress.  --DaveM
1845	 */
1846	if ((atomic_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
1847		wq = rcu_dereference(sk->sk_wq);
1848		if (wq_has_sleeper(wq))
1849			wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
1850						POLLWRNORM | POLLWRBAND);
1851
1852		/* Should agree with poll, otherwise some programs break */
1853		if (sock_writeable(sk))
1854			sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
1855	}
1856
1857	rcu_read_unlock();
1858}
1859
1860static void sock_def_destruct(struct sock *sk)
1861{
1862	kfree(sk->sk_protinfo);
1863}
1864
1865void sk_send_sigurg(struct sock *sk)
1866{
1867	if (sk->sk_socket && sk->sk_socket->file)
1868		if (send_sigurg(&sk->sk_socket->file->f_owner))
1869			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
1870}
1871EXPORT_SYMBOL(sk_send_sigurg);
1872
1873void sk_reset_timer(struct sock *sk, struct timer_list* timer,
1874		    unsigned long expires)
1875{
1876	if (!mod_timer(timer, expires))
1877		sock_hold(sk);
1878}
1879EXPORT_SYMBOL(sk_reset_timer);
1880
1881void sk_stop_timer(struct sock *sk, struct timer_list* timer)
1882{
1883	if (timer_pending(timer) && del_timer(timer))
1884		__sock_put(sk);
1885}
1886EXPORT_SYMBOL(sk_stop_timer);
1887
1888void sock_init_data(struct socket *sock, struct sock *sk)
1889{
1890	skb_queue_head_init(&sk->sk_receive_queue);
1891	skb_queue_head_init(&sk->sk_write_queue);
1892	skb_queue_head_init(&sk->sk_error_queue);
1893#ifdef CONFIG_NET_DMA
1894	skb_queue_head_init(&sk->sk_async_wait_queue);
1895#endif
1896
1897	sk->sk_send_head	=	NULL;
1898
1899	init_timer(&sk->sk_timer);
1900
1901	sk->sk_allocation	=	GFP_KERNEL;
1902	sk->sk_rcvbuf		=	sysctl_rmem_default;
1903	sk->sk_sndbuf		=	sysctl_wmem_default;
1904	sk->sk_state		=	TCP_CLOSE;
1905	sk_set_socket(sk, sock);
1906
1907	sock_set_flag(sk, SOCK_ZAPPED);
1908
1909	if (sock) {
1910		sk->sk_type	=	sock->type;
1911		sk->sk_wq	=	sock->wq;
1912		sock->sk	=	sk;
1913	} else
1914		sk->sk_wq	=	NULL;
1915
1916	spin_lock_init(&sk->sk_dst_lock);
1917	rwlock_init(&sk->sk_callback_lock);
1918	lockdep_set_class_and_name(&sk->sk_callback_lock,
1919			af_callback_keys + sk->sk_family,
1920			af_family_clock_key_strings[sk->sk_family]);
1921
1922	sk->sk_state_change	=	sock_def_wakeup;
1923	sk->sk_data_ready	=	sock_def_readable;
1924	sk->sk_write_space	=	sock_def_write_space;
1925	sk->sk_error_report	=	sock_def_error_report;
1926	sk->sk_destruct		=	sock_def_destruct;
1927
1928	sk->sk_sndmsg_page	=	NULL;
1929	sk->sk_sndmsg_off	=	0;
1930
1931	sk->sk_peercred.pid 	=	0;
1932	sk->sk_peercred.uid	=	-1;
1933	sk->sk_peercred.gid	=	-1;
1934	sk->sk_write_pending	=	0;
1935	sk->sk_rcvlowat		=	1;
1936	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
1937	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
1938
1939	sk->sk_stamp = ktime_set(-1L, 0);
1940
1941	/*
1942	 * Before updating sk_refcnt, we must commit prior changes to memory
1943	 * (Documentation/RCU/rculist_nulls.txt for details)
1944	 */
1945	smp_wmb();
1946	atomic_set(&sk->sk_refcnt, 1);
1947	atomic_set(&sk->sk_drops, 0);
1948}
1949EXPORT_SYMBOL(sock_init_data);
1950
1951void lock_sock_nested(struct sock *sk, int subclass)
1952{
1953	might_sleep();
1954	spin_lock_bh(&sk->sk_lock.slock);
1955	if (sk->sk_lock.owned)
1956		__lock_sock(sk);
1957	sk->sk_lock.owned = 1;
1958	spin_unlock(&sk->sk_lock.slock);
1959	/*
1960	 * The sk_lock has mutex_lock() semantics here:
1961	 */
1962	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
1963	local_bh_enable();
1964}
1965EXPORT_SYMBOL(lock_sock_nested);
1966
1967void release_sock(struct sock *sk)
1968{
1969	/*
1970	 * The sk_lock has mutex_unlock() semantics:
1971	 */
1972	mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
1973
1974	spin_lock_bh(&sk->sk_lock.slock);
1975	if (sk->sk_backlog.tail)
1976		__release_sock(sk);
1977	sk->sk_lock.owned = 0;
1978	if (waitqueue_active(&sk->sk_lock.wq))
1979		wake_up(&sk->sk_lock.wq);
1980	spin_unlock_bh(&sk->sk_lock.slock);
1981}
1982EXPORT_SYMBOL(release_sock);
1983
1984int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
1985{
1986	struct timeval tv;
1987	if (!sock_flag(sk, SOCK_TIMESTAMP))
1988		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
1989	tv = ktime_to_timeval(sk->sk_stamp);
1990	if (tv.tv_sec == -1)
1991		return -ENOENT;
1992	if (tv.tv_sec == 0) {
1993		sk->sk_stamp = ktime_get_real();
1994		tv = ktime_to_timeval(sk->sk_stamp);
1995	}
1996	return copy_to_user(userstamp, &tv, sizeof(tv)) ? -EFAULT : 0;
1997}
1998EXPORT_SYMBOL(sock_get_timestamp);
1999
2000int sock_get_timestampns(struct sock *sk, struct timespec __user *userstamp)
2001{
2002	struct timespec ts;
2003	if (!sock_flag(sk, SOCK_TIMESTAMP))
2004		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
2005	ts = ktime_to_timespec(sk->sk_stamp);
2006	if (ts.tv_sec == -1)
2007		return -ENOENT;
2008	if (ts.tv_sec == 0) {
2009		sk->sk_stamp = ktime_get_real();
2010		ts = ktime_to_timespec(sk->sk_stamp);
2011	}
2012	return copy_to_user(userstamp, &ts, sizeof(ts)) ? -EFAULT : 0;
2013}
2014EXPORT_SYMBOL(sock_get_timestampns);
2015
2016void sock_enable_timestamp(struct sock *sk, int flag)
2017{
2018	if (!sock_flag(sk, flag)) {
2019		sock_set_flag(sk, flag);
2020		/*
2021		 * we just set one of the two flags which require net
2022		 * time stamping, but time stamping might have been on
2023		 * already because of the other one
2024		 */
2025		if (!sock_flag(sk,
2026				flag == SOCK_TIMESTAMP ?
2027				SOCK_TIMESTAMPING_RX_SOFTWARE :
2028				SOCK_TIMESTAMP))
2029			net_enable_timestamp();
2030	}
2031}
2032
2033/*
2034 *	Get a socket option on an socket.
2035 *
2036 *	FIX: POSIX 1003.1g is very ambiguous here. It states that
2037 *	asynchronous errors should be reported by getsockopt. We assume
2038 *	this means if you specify SO_ERROR (otherwise whats the point of it).
2039 */
2040int sock_common_getsockopt(struct socket *sock, int level, int optname,
2041			   char __user *optval, int __user *optlen)
2042{
2043	struct sock *sk = sock->sk;
2044
2045	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2046}
2047EXPORT_SYMBOL(sock_common_getsockopt);
2048
2049#ifdef CONFIG_COMPAT
2050int compat_sock_common_getsockopt(struct socket *sock, int level, int optname,
2051				  char __user *optval, int __user *optlen)
2052{
2053	struct sock *sk = sock->sk;
2054
2055	if (sk->sk_prot->compat_getsockopt != NULL)
2056		return sk->sk_prot->compat_getsockopt(sk, level, optname,
2057						      optval, optlen);
2058	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2059}
2060EXPORT_SYMBOL(compat_sock_common_getsockopt);
2061#endif
2062
2063int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock,
2064			struct msghdr *msg, size_t size, int flags)
2065{
2066	struct sock *sk = sock->sk;
2067	int addr_len = 0;
2068	int err;
2069
2070	err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
2071				   flags & ~MSG_DONTWAIT, &addr_len);
2072	if (err >= 0)
2073		msg->msg_namelen = addr_len;
2074	return err;
2075}
2076EXPORT_SYMBOL(sock_common_recvmsg);
2077
2078/*
2079 *	Set socket options on an inet socket.
2080 */
2081int sock_common_setsockopt(struct socket *sock, int level, int optname,
2082			   char __user *optval, unsigned int optlen)
2083{
2084	struct sock *sk = sock->sk;
2085
2086	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2087}
2088EXPORT_SYMBOL(sock_common_setsockopt);
2089
2090#ifdef CONFIG_COMPAT
2091int compat_sock_common_setsockopt(struct socket *sock, int level, int optname,
2092				  char __user *optval, unsigned int optlen)
2093{
2094	struct sock *sk = sock->sk;
2095
2096	if (sk->sk_prot->compat_setsockopt != NULL)
2097		return sk->sk_prot->compat_setsockopt(sk, level, optname,
2098						      optval, optlen);
2099	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2100}
2101EXPORT_SYMBOL(compat_sock_common_setsockopt);
2102#endif
2103
2104void sk_common_release(struct sock *sk)
2105{
2106	if (sk->sk_prot->destroy)
2107		sk->sk_prot->destroy(sk);
2108
2109	/*
2110	 * Observation: when sock_common_release is called, processes have
2111	 * no access to socket. But net still has.
2112	 * Step one, detach it from networking:
2113	 *
2114	 * A. Remove from hash tables.
2115	 */
2116
2117	sk->sk_prot->unhash(sk);
2118
2119	/*
2120	 * In this point socket cannot receive new packets, but it is possible
2121	 * that some packets are in flight because some CPU runs receiver and
2122	 * did hash table lookup before we unhashed socket. They will achieve
2123	 * receive queue and will be purged by socket destructor.
2124	 *
2125	 * Also we still have packets pending on receive queue and probably,
2126	 * our own packets waiting in device queues. sock_destroy will drain
2127	 * receive queue, but transmitted packets will delay socket destruction
2128	 * until the last reference will be released.
2129	 */
2130
2131	sock_orphan(sk);
2132
2133	xfrm_sk_free_policy(sk);
2134
2135	sk_refcnt_debug_release(sk);
2136	sock_put(sk);
2137}
2138EXPORT_SYMBOL(sk_common_release);
2139
2140static DEFINE_RWLOCK(proto_list_lock);
2141static LIST_HEAD(proto_list);
2142
2143#ifdef CONFIG_PROC_FS
2144#define PROTO_INUSE_NR	64	/* should be enough for the first time */
2145struct prot_inuse {
2146	int val[PROTO_INUSE_NR];
2147};
2148
2149static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
2150
2151#ifdef CONFIG_NET_NS
2152void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2153{
2154	int cpu = smp_processor_id();
2155	per_cpu_ptr(net->core.inuse, cpu)->val[prot->inuse_idx] += val;
2156}
2157EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2158
2159int sock_prot_inuse_get(struct net *net, struct proto *prot)
2160{
2161	int cpu, idx = prot->inuse_idx;
2162	int res = 0;
2163
2164	for_each_possible_cpu(cpu)
2165		res += per_cpu_ptr(net->core.inuse, cpu)->val[idx];
2166
2167	return res >= 0 ? res : 0;
2168}
2169EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2170
2171static int __net_init sock_inuse_init_net(struct net *net)
2172{
2173	net->core.inuse = alloc_percpu(struct prot_inuse);
2174	return net->core.inuse ? 0 : -ENOMEM;
2175}
2176
2177static void __net_exit sock_inuse_exit_net(struct net *net)
2178{
2179	free_percpu(net->core.inuse);
2180}
2181
2182static struct pernet_operations net_inuse_ops = {
2183	.init = sock_inuse_init_net,
2184	.exit = sock_inuse_exit_net,
2185};
2186
2187static __init int net_inuse_init(void)
2188{
2189	if (register_pernet_subsys(&net_inuse_ops))
2190		panic("Cannot initialize net inuse counters");
2191
2192	return 0;
2193}
2194
2195core_initcall(net_inuse_init);
2196#else
2197static DEFINE_PER_CPU(struct prot_inuse, prot_inuse);
2198
2199void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2200{
2201	__get_cpu_var(prot_inuse).val[prot->inuse_idx] += val;
2202}
2203EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2204
2205int sock_prot_inuse_get(struct net *net, struct proto *prot)
2206{
2207	int cpu, idx = prot->inuse_idx;
2208	int res = 0;
2209
2210	for_each_possible_cpu(cpu)
2211		res += per_cpu(prot_inuse, cpu).val[idx];
2212
2213	return res >= 0 ? res : 0;
2214}
2215EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2216#endif
2217
2218static void assign_proto_idx(struct proto *prot)
2219{
2220	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
2221
2222	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
2223		printk(KERN_ERR "PROTO_INUSE_NR exhausted\n");
2224		return;
2225	}
2226
2227	set_bit(prot->inuse_idx, proto_inuse_idx);
2228}
2229
2230static void release_proto_idx(struct proto *prot)
2231{
2232	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
2233		clear_bit(prot->inuse_idx, proto_inuse_idx);
2234}
2235#else
2236static inline void assign_proto_idx(struct proto *prot)
2237{
2238}
2239
2240static inline void release_proto_idx(struct proto *prot)
2241{
2242}
2243#endif
2244
2245int proto_register(struct proto *prot, int alloc_slab)
2246{
2247	if (alloc_slab) {
2248		prot->slab = kmem_cache_create(prot->name, prot->obj_size, 0,
2249					SLAB_HWCACHE_ALIGN | prot->slab_flags,
2250					NULL);
2251
2252		if (prot->slab == NULL) {
2253			printk(KERN_CRIT "%s: Can't create sock SLAB cache!\n",
2254			       prot->name);
2255			goto out;
2256		}
2257
2258		if (prot->rsk_prot != NULL) {
2259			prot->rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s", prot->name);
2260			if (prot->rsk_prot->slab_name == NULL)
2261				goto out_free_sock_slab;
2262
2263			prot->rsk_prot->slab = kmem_cache_create(prot->rsk_prot->slab_name,
2264								 prot->rsk_prot->obj_size, 0,
2265								 SLAB_HWCACHE_ALIGN, NULL);
2266
2267			if (prot->rsk_prot->slab == NULL) {
2268				printk(KERN_CRIT "%s: Can't create request sock SLAB cache!\n",
2269				       prot->name);
2270				goto out_free_request_sock_slab_name;
2271			}
2272		}
2273
2274		if (prot->twsk_prot != NULL) {
2275			prot->twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s", prot->name);
2276
2277			if (prot->twsk_prot->twsk_slab_name == NULL)
2278				goto out_free_request_sock_slab;
2279
2280			prot->twsk_prot->twsk_slab =
2281				kmem_cache_create(prot->twsk_prot->twsk_slab_name,
2282						  prot->twsk_prot->twsk_obj_size,
2283						  0,
2284						  SLAB_HWCACHE_ALIGN |
2285							prot->slab_flags,
2286						  NULL);
2287			if (prot->twsk_prot->twsk_slab == NULL)
2288				goto out_free_timewait_sock_slab_name;
2289		}
2290	}
2291
2292	write_lock(&proto_list_lock);
2293	list_add(&prot->node, &proto_list);
2294	assign_proto_idx(prot);
2295	write_unlock(&proto_list_lock);
2296	return 0;
2297
2298out_free_timewait_sock_slab_name:
2299	kfree(prot->twsk_prot->twsk_slab_name);
2300out_free_request_sock_slab:
2301	if (prot->rsk_prot && prot->rsk_prot->slab) {
2302		kmem_cache_destroy(prot->rsk_prot->slab);
2303		prot->rsk_prot->slab = NULL;
2304	}
2305out_free_request_sock_slab_name:
2306	if (prot->rsk_prot)
2307		kfree(prot->rsk_prot->slab_name);
2308out_free_sock_slab:
2309	kmem_cache_destroy(prot->slab);
2310	prot->slab = NULL;
2311out:
2312	return -ENOBUFS;
2313}
2314EXPORT_SYMBOL(proto_register);
2315
2316void proto_unregister(struct proto *prot)
2317{
2318	write_lock(&proto_list_lock);
2319	release_proto_idx(prot);
2320	list_del(&prot->node);
2321	write_unlock(&proto_list_lock);
2322
2323	if (prot->slab != NULL) {
2324		kmem_cache_destroy(prot->slab);
2325		prot->slab = NULL;
2326	}
2327
2328	if (prot->rsk_prot != NULL && prot->rsk_prot->slab != NULL) {
2329		kmem_cache_destroy(prot->rsk_prot->slab);
2330		kfree(prot->rsk_prot->slab_name);
2331		prot->rsk_prot->slab = NULL;
2332	}
2333
2334	if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) {
2335		kmem_cache_destroy(prot->twsk_prot->twsk_slab);
2336		kfree(prot->twsk_prot->twsk_slab_name);
2337		prot->twsk_prot->twsk_slab = NULL;
2338	}
2339}
2340EXPORT_SYMBOL(proto_unregister);
2341
2342#ifdef CONFIG_PROC_FS
2343static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
2344	__acquires(proto_list_lock)
2345{
2346	read_lock(&proto_list_lock);
2347	return seq_list_start_head(&proto_list, *pos);
2348}
2349
2350static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2351{
2352	return seq_list_next(v, &proto_list, pos);
2353}
2354
2355static void proto_seq_stop(struct seq_file *seq, void *v)
2356	__releases(proto_list_lock)
2357{
2358	read_unlock(&proto_list_lock);
2359}
2360
2361static char proto_method_implemented(const void *method)
2362{
2363	return method == NULL ? 'n' : 'y';
2364}
2365
2366static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
2367{
2368	seq_printf(seq, "%-9s %4u %6d  %6d   %-3s %6u   %-3s  %-10s "
2369			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
2370		   proto->name,
2371		   proto->obj_size,
2372		   sock_prot_inuse_get(seq_file_net(seq), proto),
2373		   proto->memory_allocated != NULL ? atomic_read(proto->memory_allocated) : -1,
2374		   proto->memory_pressure != NULL ? *proto->memory_pressure ? "yes" : "no" : "NI",
2375		   proto->max_header,
2376		   proto->slab == NULL ? "no" : "yes",
2377		   module_name(proto->owner),
2378		   proto_method_implemented(proto->close),
2379		   proto_method_implemented(proto->connect),
2380		   proto_method_implemented(proto->disconnect),
2381		   proto_method_implemented(proto->accept),
2382		   proto_method_implemented(proto->ioctl),
2383		   proto_method_implemented(proto->init),
2384		   proto_method_implemented(proto->destroy),
2385		   proto_method_implemented(proto->shutdown),
2386		   proto_method_implemented(proto->setsockopt),
2387		   proto_method_implemented(proto->getsockopt),
2388		   proto_method_implemented(proto->sendmsg),
2389		   proto_method_implemented(proto->recvmsg),
2390		   proto_method_implemented(proto->sendpage),
2391		   proto_method_implemented(proto->bind),
2392		   proto_method_implemented(proto->backlog_rcv),
2393		   proto_method_implemented(proto->hash),
2394		   proto_method_implemented(proto->unhash),
2395		   proto_method_implemented(proto->get_port),
2396		   proto_method_implemented(proto->enter_memory_pressure));
2397}
2398
2399static int proto_seq_show(struct seq_file *seq, void *v)
2400{
2401	if (v == &proto_list)
2402		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
2403			   "protocol",
2404			   "size",
2405			   "sockets",
2406			   "memory",
2407			   "press",
2408			   "maxhdr",
2409			   "slab",
2410			   "module",
2411			   "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
2412	else
2413		proto_seq_printf(seq, list_entry(v, struct proto, node));
2414	return 0;
2415}
2416
2417static const struct seq_operations proto_seq_ops = {
2418	.start  = proto_seq_start,
2419	.next   = proto_seq_next,
2420	.stop   = proto_seq_stop,
2421	.show   = proto_seq_show,
2422};
2423
2424static int proto_seq_open(struct inode *inode, struct file *file)
2425{
2426	return seq_open_net(inode, file, &proto_seq_ops,
2427			    sizeof(struct seq_net_private));
2428}
2429
2430static const struct file_operations proto_seq_fops = {
2431	.owner		= THIS_MODULE,
2432	.open		= proto_seq_open,
2433	.read		= seq_read,
2434	.llseek		= seq_lseek,
2435	.release	= seq_release_net,
2436};
2437
2438static __net_init int proto_init_net(struct net *net)
2439{
2440	if (!proc_net_fops_create(net, "protocols", S_IRUGO, &proto_seq_fops))
2441		return -ENOMEM;
2442
2443	return 0;
2444}
2445
2446static __net_exit void proto_exit_net(struct net *net)
2447{
2448	proc_net_remove(net, "protocols");
2449}
2450
2451
2452static __net_initdata struct pernet_operations proto_net_ops = {
2453	.init = proto_init_net,
2454	.exit = proto_exit_net,
2455};
2456
2457static int __init proto_init(void)
2458{
2459	return register_pernet_subsys(&proto_net_ops);
2460}
2461
2462subsys_initcall(proto_init);
2463
2464#endif /* PROC_FS */
2465